Field of the Invention
The present invention relates to a structure of a connector, and more particularly, to a structure of a connector used to connect a ground pin to an electric motor or brake.
Description of the Related Art
A connector connected to an electric motor or brake is provided with a ground wire, which is electrically connected to the body of the motor or brake to prevent a shock hazard in case of electrical leakage. A conventional connector based on resin molding around pins is made conductive to the brake or motor body by a fixture through a wire or the like extending from a ground pin.
FIG. 7 is a view illustrating an electric motor with a brake. The motor comprises the brake and a rotation detector. As shown in FIG. 7, a power connector 4 is attached to a body 2 of the motor, and a brake connector 5 is attached to a body 3 of the brake. Reference numeral 6 denotes the body of the detector.
FIGS. 8 and 9 are views illustrating a prior art technique in which a ground pin and a motor body are made conductive to each other by a wire. As shown in FIGS. 8 and 9, the power connector 4 is attached to the motor body 2. An end portion of a ground pin 7 of the power connector 4 on the side of the motor body 2 and a fixture 17 secured to the motor body 2 are electrically connected to each other by a wire 16 for conduction.
In the technique illustrated in FIGS. 8 and 9, the boundary between a cable 26 and a connector cover 46 of a cable-side connector 9 is waterproofed by tightening a bushing 47 and the connector cover 46 by means of a cable clamp 48. Further, the boundary between the cable-side connector 9 and a connector (body-side connector) 8 on the side of the motor body 2 is waterproofed by tightening a gasket 34 (sealing portion 14 between the body-side and cable-side connectors) at the boundary between the connector cover 46 and the body-side connector 8 by means of cable-side connector mounting fixtures 12. Furthermore, the boundary between the body-side connector 8 and the motor body 2 is waterproofed by tightening a gasket 10, for use as a sealing portion 13 (FIG. 9) between the body-side connector 8 and the motor body 2, by means of a body-side connector mounting fixture 11.
Japanese Patent Application Laid-Open No. 11-289702 discloses an electric motor with its stator coil supplied with electric power, in which a stator core of the circuit board is connected to a ground pin of a power line connector by a bolt, annular plate, and ground wire. Further, Japanese Patent Application Laid-Open No. 2004-319277 discloses a waterproof shield structure in which a ground terminal is crimped to the end of a shield of a shield cable.
According to the prior art technique described above with reference to FIGS. 8 and 9, it is time-consuming to make the ground pin conductive to the brake or motor body. To save time, therefore, it is proposed to make this conduction by a connector mounting fixture. This technique will now be described with reference to FIGS. 10 and 11.
FIGS. 10 and 11 are views illustrating a prior art technique in which a ground pin is made conductive to a motor body by a connector mounting fixture.
A cable-side connector 9 is secured to a body-side connector 8 by cable-side connector mounting fixtures 12. A ground pin 7 is electrically connected to a motor body 2 through a conduction portion 7b and a bridge portion 7a. The bridge portion 7a extends from a side surface of an end portion of the ground pin 7 on the side of the motor body 2 toward the conduction portion 7b. The conduction portion 7b covers the outer periphery of a body-side connector mounting fixture 11 and electrically connects it to the motor body 2.
In the technique shown in FIGS. 10 and 11, however, the ground pin 7 and the motor body 2 are made conductive to each other by the fixture (not by the wire 16 shown in FIGS. 8 and 9 or the like), so that a path is inevitably formed between a body-interior-portion side 15 and an atmosphere side 18 of the motor through the conduction portion 7b, bridge portion 7a extending to the conduction portion 7b, and ground pin 7.